Dante04SRT
Petty Officer 1st Class
- Joined
- Jun 30, 2007
- Messages
- 311
OK, I did another compression test tonight, both a dry and a wet test.
Here is what I got, and before anyone asks, the gauge is new and tested fine on my car.
--DRY-- (cylinder order is front of boat to back)
#1: 39-40lbs
#2: 30lbs
#3: 69-70lbs
#4: 165-170
--WET-- (with thick motor oil)
#1: 55lbs
#2: 45lbs
#3: 95lbs
#4: Started to rain, figured it was fine because of initial readings.
What am I to understand about these readings? I can see by adding the oil to the cylinder, pressures were increased, but not by any substantial amount. Its a 20 year old motor, a little ring gap issue is expected, right?
I definitely have a problem, as evidence by the results, also, when doing the tests dry, the motor spit water out of either #2 or #3, couldn't tell. I live in TN where the weather rarely reaches freezing, and even if it does, its not there but a day or so, so I'm HOPING that cracked block/head issues aren't there. The boat actually ran very good, as shown in the attached video link.
http://www.youtube.com/watch?v=a3EqwR-Bods
By reading the results, is there any reason to still suspect a head gasket issue? Can any other inferences be made? If everyone generally agrees, I will tear the head off tomorrow evening.
Thanks in advance, ppl.
[EDIT] If you haven't been following my previous posts, here's what started all of the investigation:
#1: Motor had to be WOT and cranked for 10 seconds to start
#2: Wouldn't idle at all
#3: Didn't have much power
#4: Took forever to plane (literally 2-3 minutes)
#5: Motor has slight knock at certain rpms when under load, sounds like rod knock, but not very deep. The knocking sound is not constant, it sometimes comes and goes, unlike any rod knock I've heard before.
#6: Timing was fine
Here is what I got, and before anyone asks, the gauge is new and tested fine on my car.
--DRY-- (cylinder order is front of boat to back)
#1: 39-40lbs
#2: 30lbs
#3: 69-70lbs
#4: 165-170
--WET-- (with thick motor oil)
#1: 55lbs
#2: 45lbs
#3: 95lbs
#4: Started to rain, figured it was fine because of initial readings.
What am I to understand about these readings? I can see by adding the oil to the cylinder, pressures were increased, but not by any substantial amount. Its a 20 year old motor, a little ring gap issue is expected, right?
I definitely have a problem, as evidence by the results, also, when doing the tests dry, the motor spit water out of either #2 or #3, couldn't tell. I live in TN where the weather rarely reaches freezing, and even if it does, its not there but a day or so, so I'm HOPING that cracked block/head issues aren't there. The boat actually ran very good, as shown in the attached video link.
http://www.youtube.com/watch?v=a3EqwR-Bods
By reading the results, is there any reason to still suspect a head gasket issue? Can any other inferences be made? If everyone generally agrees, I will tear the head off tomorrow evening.
Thanks in advance, ppl.
[EDIT] If you haven't been following my previous posts, here's what started all of the investigation:
#1: Motor had to be WOT and cranked for 10 seconds to start
#2: Wouldn't idle at all
#3: Didn't have much power
#4: Took forever to plane (literally 2-3 minutes)
#5: Motor has slight knock at certain rpms when under load, sounds like rod knock, but not very deep. The knocking sound is not constant, it sometimes comes and goes, unlike any rod knock I've heard before.
#6: Timing was fine
I'll probably get the head off tomorrow after work, hopefully all goes smooth and it turns out to be the head gasket. --fingers crossed--
